Mr Walesa, due to hand over power to a former Communist, Aleksander Kwasniewski, on Saturday, refused to spell out the nature of the allegations in detail. But unnamed sources cited by Polish media said they concerned long-standing contacts between Mr Oleksy and foreign espionage agents.
Mr Oleksy, himself a former Communist, described the allegations as a "dirty provocation", suggesting Mr Walesa was having difficulty accepting his defeat at the hands of Mr Kwasniewski in last month's presidential election.
Appearing on television last night, Mr Oleksy accused the President and the security services of trying to force his resignation by smearing him. "I will not give in to blackmail. I do not plan to break and step down," he said in a strongly-worded address to the nation.
An emergency cabinet meeting convened to consider Mr Walesa's evidence ruled that it had not proved the security of the state was endangered. The President, present at the meeting, dissented from its view.
Most Poles were dumbfounded by the allegations. Many saw Mr Walesa's move as a last-ditch attempt to use the authority of his office to discredit his former Communist political opponents and launch a new career as leader of the opposition.
"It is difficult not to see this as a spoiling tactic," a Western diplomatic source said. "It certainly appears to have been timed to make life difficult for the incoming President."
Yesterday's uproar followed a late-night meeting at the presidential palace on Tuesday to which the speakers of both houses of parliament and the country's top legal authorities had been invited. Andrzej Milczanowski, the Interior Minister and a Walesa ally, presented the meeting with confidential documents which allegedly revealed the security threat and incriminated Mr Oleksy. Mr Milczanowski reported he had presented the documents to the senior military prosecutor.
With hard facts in short supply, the Polish media ran wild with rumour. Mr Oleksy was alleged to have had contacts with Soviet and Russian spies from 1983 until he took office earlier this year. Others suggested he had laundered Communist Party money. Some reported the existence of videos showing him playing tennis with Soviet agents.
Mr Oleksy, who along with Mr Kwasniewski was not invited to the Tuesday meeting, called for an immediate session of the National Defence Committee to consider the evidence. He was sharply critical of Mr Walesa. "What has been done demonstrates that state security may be threatened - but by those who cannot leave their posts in a dignified fashion," Mr Oleksy said.
Mr Walesa's narrow defeat to Mr Kwasniewski last month means that, in addition to the government, Poland's former Communists will now control the presidency. But the outgoing President, who once led the Solidarity trade union that toppled Communism, has refused to take his defeat lying down.
Shortly after the election, in an attempt to have the result annulled, more than 500,000 supporters filed protests with the Supreme Court complaining Mr Kwasniewski had lied about his academic qualifications during the campaign.
Mr Walesa has begun travelling the country to unite Poland's fractured right before parliamentary elections in 1997.Reuse content